During the coming year, the following studies will be conducted: a. The effects of acetazolamide, furosemide and the HCO minus 3 - CO2 buffer system pH, Na ion, Cl, HCO minus 3 transport, p.d. and permeability on the isolated eccrine secretory coil duct in vitro. b. Completion of studies to determine transepithelial and cell membrane potential differences and cell membrane input impedance on the isolated eccrine secretory coil. c. Completion of studies to clarify the similarities and dissimilarities in function between the rat eccrine gland and the insect salivary gland by comparing their responses to acetazolamide, cyanide, dinitrophenol, cAMP and cGMP and by determining values for hydraulic conductivity and reflection coefficient for NaCl. These studies will determine whether the insect salivary gland will provide a useful, less complex model.